Electric selecting device responsive to impulses



Mal'Ch 16, 1954 W, Q FOSTER 2,672,599

y v ELECTRIC SELECTING DEVICE RESPONSIVE TO IMPULSES Filed March 24,1952 @JM L Patented Mar. 16, 1954 ELECTRIC sELECTING DEVICE RESPONSIVE'ro IMPULsEs William Gordon Foster, London, England, as-

sgnor to Telephone Manufacturing Company Limited, London, England, aBritish company Application March 24, 1952, Serial No. 278,162

Claims priority, application Great Britain l April 2, 1951 Thisinvention relates to electric selecting devices responsive to impulses.

Electric selecting devices responsive to impulses are well known in thetelephone and other arts for counting a number of impulses and forperforming or causing the performance of desired operations independence upon the number of impulses. They are mainly of one or otherof two kinds, namely of step-by-step electro-mechanical switches or ofrelay chains.

The present invention is concerned with an electric selecting deviceresponsive to impulses, which partakes more of the nature of a relayselecting chain rather than of a step-by-step electro-mechanical switch,and makes use of socalled selective relay units to perform the operationof selection in response to impulses and, it may be, to perform or tocause to be performed a desired operation.

The term selective relay unit denotes a device which consists of anelectro-magnetic relay having a plurality of sets of contacts, a lingermagnet being associated with each set of contacts, each finger magnet,when energized serving to interpose a finger between its associated setof contacts and the armature of the relay so that only the set ofcontacts associated with the energized finger magnet is operateduponwhen the armature of the relay is actuated. v

In our patent specification Serial No. 159,321 we have described anelectric selecting device comprising selective relay units andresponsive to impulses. The electric selecting device therein describedcomprises ten selective relay units and is capable of counting up to amaximum of ten impulses. In the System therein described, the selectiverelay units have other duties to perform in dependence upon the numberof impulses counted, that is the ten selective relay units are requiredto connect a particular circuit to any one of one hundred othercircuits, each selective relay unit being capable of connecting the saidone circuit to any one of ten such other circuits. When such is therequirement, there is no objection to the provision of ten selectiverelay units. When, however, the maximum number of such other circuits istwenty arranged in ten numerical groups of two circuits per groupa-requrement which can be satised by two selective relay units, it ismanifestly undesirable to have to provide ten selective relay units,eight of which are provided for no other purpose than that of countingimpulses. 1

The present invention, .by permitting the finger magnets of theselective relay units to take part 5 Claims. (Cl. 340-168) in theYnumerical selecting operation makes it possible to perform or tocontrol the performance of any one of 2n operations by means of twoselective relay units each having n linger magnets.

According to the present invention, an electric selecting devicecomprises two selective relay units, each having n linger magnets, saidselective relay units being adapted to be operated in alternation inresponse to impulses and each, when operated, closing a circuit for afinger magnet of the other, so that the linger magnets of one selectiverelay unit are operated in succession in response to odd-numberedimpulses and those of the other are operated in succession in responseto even-numbered impulses,` the electric selecting device being thusable selectively to perform or to control the performance of any one of2n operations.

.The invention is illustrated in the accompanying drawings of which Fig.1 illustrates a selective relay unit and Fig. 2 is a circuit diagramillustrating the invention.

A selective relay unit (hereinafter referred to as a SRU) as illustratedquite diagrammatically in Fig. 1 consists of five sets of contactsnumbered respectively l-E, an armature AR, an energizing magnet SR andfive fingers, shown as points, one to the left of each set of contacts.A nger magnet (not shown) is associated with each linger. If, with allthe fingers in the positions indicated the armature AR is operated,

it will be unable to operate any of the contacts.

If, on the other hand, any finger is moved to the right so as to comebetween its associated bank of contacts and the armature, and after thisthe armature is operated, the bank of contacts concerned will beoperated. Thus a means 1s provided for selecting, by energization of anyone of the finger magnets, any one of the sets of contacts I-5.

Referring now to Figure 2, an electric selecting device responsive toimpulses is shown. This consists of two SRUs and a number of otherrelays and circuits.

One of the SRUs, namely that given the general reference SRUI, isrepresented vby its energizing magnet SRI, its armature ARI, ve fingermagnets FMI, FMB, FMS, FMT, FMS, ve fingers respectively fl, f3, f5, f1,fg, and five sets of contacts srHa). SRUI also has certainothercontacts, which are operated every time an armature ARI operates,indicated by the reference srl followed by a solidus and a numeral. SRUImay also have other contacts Relays B and C are retarded releaserelays-` and relay IP is an impulse-relay respoizlsiveA toIinterruptions by the line circuit for deliweisilflgv impulses from itscontact ipl to the electric selecting device constituted by the two:SRUis.

All the relay contacts in Eu'igure are; repre sented in their normal (atresti positions andfalll the coils are die-energized. Operation asiolflows: switch S, which if the electric selecting device forms part of atelephonesystem; maybe ated the line circuit is interrupted a certainnuinf ber of times, depending on the value of the digit being dialled,`and the relay IP is tie-energized` a` corresponding number oi'ftirnes,

The. first time relay Il? cle-energizes it closes a circuit from earthv-ia contacts 'ipl (ba-cir), bl

(front) and swt (bac-31e)- for-energizi-ng magnetvr It also. closes arrobvious circuit for` relayV SR-t; C` Both-SR1 andsCwillbecome-energized;SR? operates. its armature and' thereby closes acire cuit for lingermagnet Flr/l2, from earth, via. contacts b2'y (front), c2 (front) SRU@number one,` iflngerimagnet to nega-tive.-

SRifalsotcloses a holding circuit from earth by Way of contacts b3(front.)` crit/2- (back-l, srt/l (fronti, througnwinding of relay SW andthe winding of' SR1 i. Relayf SW' does notV operate in thiscircuitas.it;.has earth connected to both sides of its winding; that is via theconnection-l just traced to. one side, and from earth, via` con tacts,rini (back). hl (front). and sw (ba-ck): to the .other side.

Wfhen relay; IR re-operatesthe .short circuit is removed .from relay: SWand this relay now operalles;

Whenreiay iPf releases for the secondI impulseacircuitiscempletedforenergizing Winding SR2, this circuit oe-ing from. earth via ipl (back),bi (fron-t) swl (iront), and 3x2/'I (back). SRZJopcrates its armatureAEZ, and by reason of thefactvthat finger fis between contactsSRc)Anumber two and armature ARZ', these latterfcon tacts are closed and acircuit is thereby completed.

foringer. megnetFll/IS, the circuit being similar to that for' EME'.SR2.r also; transfers itself: into..

a holding circuit; by way of' earth, contact` b2 (front), contact S102(front) and-Jrnahe-before-- break contacts. srt/l (front At sr2/2r'itopens a circuit` forrelay and the holding.:.circuit of. SR1; SW vis:still held, however, in a circuit fromr earth by way of contacts zpl(bachi), b1' (fronti) andstct; (front), ,to negative. SRI derenergizesandtclosesatsrl/Z an alternative. hol'dingcircuit. toi-.1 SR2:thisalternative holding circuiti isN from; eartln. via; contacts.r b2(front )1, sri! 2J (back )l, mi2/t (front). anx1-.the-winding ofSRZtonegative;

this circuit-being At the end of this second impulse, when relay IPre-operates, the circuit for relay SW is opened and this relay releases,SR2 however, remaining held.

In response; ta the third: impulsa SR1! again becomes energized' andatcontactsl SRI'uz) number three, closes a circuit for finger magnetFM4. E?. is thought unnecessary to trace the operations any.. iuether asthey should be suiciently clear i isomthe description already given.

For the present description it may be supposed that onlyrtwo impulseshave to be counted. Underfsuch a supposition we are now at the positionlthat SR@ energized with inger i2 between, contacts, SRMa) number two andarmature ARZ, and that these contacts are closed. Al'socontacts swr-2th)number two are closed. BMK is energized but has no elect until SRIshouldbe operated in response to three impulses (which in the presentsupposition we have exc1uded)..

Since no further impulses are, to be received contactv ipl will be heldaway from its resting position and" relay C consequently release after ashortl delay. Relay/Cat ccnt'act'c (fronti Will open the circuit forfinger magnet FMG-'arid at' contact c2' (ba-cle) Will close a circuit byway of` contact SR2-(li) number twoA fortheperforrnance` or control ofdesiredoperati'on number two:

Iclaim:

l. An electric selective device responsive` to:

impulses from a. source of impulses, saidi device including twoselective relay units each-- having' a plurality'of sets of: contacts,-an armature, anl energizing coil', a plurality offingers one asso;-

citedl'witheach set of contacts-fop interposition.

between said set of'contacts andsaid armature,A a likeplurality offinger magnets onev associated.

with each 'ng for, interposing-whenV energizedI its associated ngerbetween aseti of! contacts.

and saidarmature, andconnections betweensets ofcontacts-.oi eachselective relay unit andi` fingermagnets of thefotherrselectiverela-yunitfso-that.

each selective relayunit. .whenl energizedcloses: an energizing circuitthrough one sety ofiits con@ tacts and" one finger magnet of theotherselective relay-:uniti said; selective device further including`4 pulsesfrom said source tosaidenergizing coils;r

includes a. switchingrelay having a changeover contact; a iront :contactand a1backcontactla connection .from the changedvercontact. to,y saldasourcerof. impulses, .aconnection from saiclft'ont: contact: to.. theAenergizingl winding ofv one, selec.. tive-relay unit, and aconnectionf'fromssaidibaclc Contact: to the energizing winding. of the other-`sel'ective relay unit, and. circuitl means-from said' sourceofi impulsesthrough contacts ofsaict se lectivaV relay. units to. said switching.relay for operating said switching` relay in responsezto.

impulses from asource oi"impulses-, said'device'4 including twoselective relay units each havinglal plurality of sets of contacts; an.armature;y an.

energizing, coil, a plurality of'-ngers, oneA associated .with eachset-of" contacts for 'interposition between said setfofcontactssaidfarmature; a-

like pluralityy oififinger magnets, one associated with each finger forinterposingewhen'energizedi itsf associatedE fingen between A a: setiVof; contacts and said armature, connections between sets of contacts ofeach selective relay unit and finger magnets of the other Selectiverelay unit so that each selective relay unit when energized closes anenergizing circuit through one set of its contacts and one iinger magnetcf the other selective relay unit, said selective device further including switching means for directing odd-numbered impulses from saidsource of impulses to the winding of one of said selective relay unitsand even-numbered impulses from said source of impulses to the windingof the other of said selective relay units.

4. An electric selective device as set forth in claim 3, wherein saidswitching means includes a switching relay having two windings, achangeover contact, a front Contact and a back contact, a connectionfrom the changeover contact to said source of impulses, a connectionfrom said front contact to the energizing winding of said one selectiverelay unit, and a connection from said back contact to the energizingwinding of the other selective relay unit, a further connection fromsaid front contact to one of said two windings and a further connectionfrom said baci: Contact to the other of said two windings, said furtherconnection from said back contact including a front contact on said oneselective relay unit and a front -contact on said other selective relayunit,

5. An electric selecting device responsive to impulses, comprising incombination a source of impulses, a rst relay, a second relay, switchingmeans, circuit means including said switching means for directingimpulses from said source of impulses to said rst and second relays inalternation thereby to operate them in alternation, a plurality of setsof contacts for each of said first and second relays, means forselecting sets of contacts of said first relay one at a time, means foroperating the selected set of contacts, means for selecting sets ofcontacts of said second relay one at a time, means for operating theselected sets of contacts, and means including said sets of contacts ofeach said relay for operating ths operating means of the othen relay,whereby said first and said second relays effect a progressive selectionof said sets of contacts.

WILLIAM GORDON FOSTER.

References #Cited in the le of this patent UNTTED STATES PATENTS NumberName Date 2,305,450 Stibitz Dec. 15, 1942 v2,314,187 Abbot Mar. 16, 19432,456,169 Bellamy Dec. 14, 1948 2,538,815 Bellamy Jan. 23, 1951

